Dual-core focusing image sensor, focusing control method for the same, and electronic device

ABSTRACT

The present disclosure discloses a dual-core focusing image sensor, a focusing control method for the same and an electronic device. The dual-core focusing image sensor includes an array of photosensitive pixels, an array of filter units arranged on the array of photosensitive pixels and an array of micro lenses arranged above the array of filter units. The array of micro lenses includes at least one first micro lens and a plurality of second micro lenses, each second micro lens is corresponding to one photosensitive pixel, each first micro lens is corresponding to one focusing photosensitive unit, each focusing photosensitive unit includes N*N photosensitive pixels, and at least a part of the focusing photosensitive unit is covered by a white filter unit, where N is an even number greater than or equal to 2.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No.201710297649.8, filed on Apr. 28, 2017, the entire contents of which areincorporated herein by reference.

FIELD

The present disclosure relates to the image device technology field, andmore particularly to a dual-core focusing image sensor, a focusingcontrol method for the same, and an electronic device.

BACKGROUND

In the related art, Dual Pixel Autofocus technology has become the mostadvanced focusing technology on the market. Compared with contrastfocusing, laser focusing and phase focusing technologies, the Dual PixelAutofocus technology has faster focusing speed and wider focusing range.In addition, in the Dual Pixel Autofocus technology, since “dual-core”photodiodes are “merged” as one pixel to output during imaging,performance of focusing can be guaranteed without affecting the imagequality.

However, when using the Dual Pixel Autofocus technology, since there aretwo photodiodes for each pixel, the amount of light is reduced, thuscausing it difficult to perform a dual-core focusing in low lightenvironment.

SUMMARY

Embodiments of a first aspect of the present disclosure provide afocusing control method for a dual-core focusing image sensor. Thedual-core focusing image sensor includes an array of photosensitivepixels, an array of filter units arranged on the array of photosensitivepixels, and an array of micro lenses arrange above the array of filterunits. The array of micro lenses includes at least one first micro lensand a plurality of second micro lenses, each second micro lens iscorresponding to one photosensitive pixel, and each first micro lens iscorresponding to one focusing photosensitive unit. Each focusingphotosensitive unit includes N*N photosensitive pixels, and at least apart of the focusing photosensitive unit is covered by a white filterunit, where N is an even number greater than or equal to 2. The methodincludes: controlling the array of photosensitive pixels to enter afocus mode; obtaining first phase difference information of the focusingphotosensitive unit and second phase difference information of thephotosensitive pixel corresponding to the second micro lens; andperforming focusing control according to the first phase differenceinformation and the second phase difference information.

Embodiments of a second aspect of the present disclosure provide adual-core focusing image sensor, including an array of photosensitivepixels, an array of filter units arranged on the array of photosensitivepixels and an array of micro lenses arranged above the array of filterunits. The array of micro lenses includes at least one first micro lensand a plurality of second micro lenses, each second micro lens iscorresponding to one photosensitive pixel, each first micro lens iscorresponding to one focusing photosensitive unit, each focusingphotosensitive unit includes N*N photosensitive pixels, and at least apart of the focusing photosensitive unit is covered by a white filterunit, where N is an even number greater than or equal to 2.

Embodiments of a third aspect of the present disclosure provide anelectronic device. The electronic device includes the dual-core focusingimage sensor according to the embodiments of the first aspect of thepresent disclosure and a controller. The controller is configured to:control the array of photosensitive pixels to enter a focus mode;generate first phase difference information of the focusingphotosensitive unit and second phase difference information of thephotosensitive pixel corresponding to the second micro lens; and performfocusing control according to the first phase difference information andthe second phase difference information.

Additional aspects and advantages of embodiments of present disclosurewill be given in part in the following descriptions, become apparent inpart from the following descriptions, or be learned from the practice ofthe embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the presentdisclosure will become apparent and more readily appreciated from thefollowing descriptions made with reference to the drawings, in which:

FIG. 1 is a schematic diagram of a dual-core focusing image sensor inthe related art;

FIG. 2 is a section view of a dual-core focusing image sensor accordingto an embodiment of the present disclosure;

FIG. 3 is a top view of a dual-core focusing image sensor according toan embodiment of the present disclosure;

FIG. 4 is a diagram illustrating a density arrangement of first microlenses;

FIG. 5 is a flow chart of a focusing control method for a dual-corefocusing image sensor according to an embodiment of the presentdisclosure;

FIG. 6 is a schematic diagram illustrating a dividing effect of 2*2photosensitive pixels covered by a white filter unit in a focusingphotosensitive unit according to an embodiment of the presentdisclosure;

FIG. 7 is a flow chart of a focusing control method for a dual-corefocusing image sensor according to another embodiment of the presentdisclosure;

FIG. 8 is a schematic diagram of obtaining pixel values of a focusingphotosensitive unit by an interpolation algorithm;

FIG. 9 is a block diagram of an electronic device according to anembodiment of the present disclosure;

FIG. 10 is a block diagram of an electronic device according to anembodiment of the present disclosure.

EMBODIMENTS OF THE PRESENT DISCLOSURE

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in accompanying drawings, in which the same orsimilar reference numbers throughout the drawings represent the same orsimilar elements or elements having same or similar functions.Embodiments described below with reference to drawings are merelyexemplary and used for explaining the present disclosure, and should notbe understood as limitation to the present disclosure.

The present disclosure is related to a focusing control method for adual-core focusing image sensor. The dual-core focusing image sensorincludes an array of photosensitive pixels, an array of filter unitsarranged on the array of photosensitive pixels, and an array of microlenses arrange above the array of filter units. The array of microlenses includes at least one first micro lens and a plurality of secondmicro lenses, each second micro lens is corresponding to onephotosensitive pixel, and each first micro lens is corresponding to onefocusing photosensitive unit. Each focusing photosensitive unit includesN*N photosensitive pixels, and at least a part of the focusingphotosensitive unit is covered by a white filter unit, where N is aneven number greater than or equal to 2. The method includes: controllingthe array of photosensitive pixels to enter a focus mode; obtainingfirst phase difference information of the focusing photosensitive unitand second phase difference information of the photosensitive pixelcorresponding to the second micro lens; and performing focusing controlaccording to the first phase difference information and the second phasedifference information.

The present disclosure is further related to a dual-core focusing imagesensor. The dual-core focusing image sensor includes an array ofphotosensitive pixels, an array of filter units arranged on the array ofphotosensitive pixels and an array of micro lenses arranged above thearray of filter units. The array of micro lenses includes at least onefirst micro lens and a plurality of second micro lenses, each secondmicro lens is corresponding to one photosensitive pixel, each firstmicro lens is corresponding to one focusing photosensitive unit, eachfocusing photosensitive unit includes N*N photosensitive pixels, and atleast a part of the focusing photosensitive unit is covered by a whitefilter unit, where N is an even number greater than or equal to 2.

The present disclosure is further related to an electronic device. Theelectronic device includes a dual-core focusing image sensor and acontroller. The dual-core focusing image sensor includes an array ofphotosensitive pixels, an array of filter units arranged on the array ofphotosensitive pixels and an array of micro lenses arranged above thearray of filter units. The array of micro lenses includes at least onefirst micro lens and a plurality of second micro lenses, each secondmicro lens is corresponding to one photosensitive pixel, each firstmicro lens is corresponding to one focusing photosensitive unit, eachfocusing photosensitive unit includes N*N photosensitive pixels, and atleast a part of the focusing photosensitive unit is covered by a whitefilter unit, where N is an even number greater than or equal to 2. Thecontroller is configured to: control the array of photosensitive pixelsto enter a focus mode; generate first phase difference information ofthe focusing photosensitive unit and second phase difference informationof the photosensitive pixel corresponding to the second micro lens; andperform focusing control according to the first phase differenceinformation and the second phase difference information.

The present disclosure is further related to an electronic device. Theelectronic device includes a housing, a processor, a memory, a circuitboard and a power supply circuit. The circuit board is arranged inside aspace enclosed by the housing. The processor and the memory are arrangedon the circuit board. The power supply circuit is configured to providepower for respective circuits or components of the electronic device.The memory is configured to store executable program codes. Theprocessor is configured to run a program corresponding to the executableprogram codes by reading the executable program codes stored in thememory, to perform the above-mentioned focusing control method.

The dual-core focusing image sensor, the focusing control method for thedual-core focusing image sensor, and the electronic device according toembodiments of the present disclosure will be described below withreference to accompanying drawings.

The Dual Pixel Autofocus technology is the most advanced focusingtechnology on the market. FIG. 1 illustrates the structure of thedual-core focusing sensor used in this focusing technology. Asillustrated in FIG. 1, each micro lens (in FIG. 1, circles representmicro lenses) corresponds to one photosensitive pixel, and eachphotosensitive pixel has two photodiodes. In an imaging process, valuesof “1” and “2” are added to obtain a single-component pixel value. In afocusing process, the values of “1” and “2” are read respectively, and adriving force and a driving direction of the lens can be determined bycalculating a phase difference between the values of “1” and “2”.

It may be understood that, with an increase of the total number ofpixels, photosensitive areas corresponding to “1” and “2” becomesmaller, so that the amount of passed light is reduced, the phaseinformation is easily drowned by noise in the low light environment, andit is difficult to perform focusing in the low light environment.

Therefore, in order to solve the problem in the Dual Pixel Autofocustechnology in the related art that the focusing is difficult in the lowlight environment, the present disclosure provides a dual-core focusingimage sensor, which can increase the amount of light passing through thefocusing pixel, and effectively improve a focusing speed in low lightenvironment, while ensuring an accuracy of color reduction of an image.

In the following, the dual-core focusing image sensor according toembodiments of the present disclosure is described.

FIG. 2 is a section view of a dual-core focusing image sensor accordingto an embodiment of the present disclosure. FIG. 3 is a top view of adual-core focusing image sensor according to an embodiment of thepresent disclosure.

As illustrated in FIG. 2 and FIG. 3, the dual-core focusing image sensor100 includes an array 10 of photosensitive pixels, an array 20 of filterunits and an array 30 of micro lenses.

The array 20 of filter units is arranged on the array 10 ofphotosensitive pixels, and the array 30 of micro lenses is arrangedabove the array 20 of filter units. The array 30 of micro lensesincludes at least one first micro lens 31 and a plurality of secondmicro lenses 32. Each second micro lens is corresponding to onephotosensitive pixel 12. Each first micro lens 31 is corresponding toone filter unit 22 and one focusing photosensitive unit 11. Eachfocusing photosensitive unit 11 includes N*N photosensitive pixels 12.In an embodiment, as illustrated in FIG. 3, one focusing photosensitiveunit 11 (the area enclosed by dotted lines in FIG. 3) includes 2*2photosensitive pixels 12. At least a part of the focusing photosensitiveunit 11 is covered by a white filter unit 21. In the present disclosure,“covered by a white filter unit” could be understood in broad sense. Forexample, in an embodiment of the present disclosure, at least a part ofthe focusing photosensitive unit is not covered by a filter unit. Asillustrated in FIG. 2, the filter unit in the part 21 may be removed ormay be replaced by a white filter unit. In an embodiment, thephotosensitive pixel under the part 21 can be referred to as “white”pixel.

The photosensitive pixel 12 has two photodiodes, which are a firstphotodiode 121 and a second photodiode 122 respectively. The firstphotodiode 121 and the second photodiode 122 correspond to “1” and “2”of each photosensitive pixel 12 in FIG. 3, respectively.

In embodiments of the present disclosure, the photosensitive pixels 12are arranged in a Bayer array. By using the Bayer structure, theconventional algorithm for the Bayer structure can be used to processimage signals, so that there is no need to make great adjustment interms of hardware structure.

In embodiments of the present disclosure, the white filter unit 21covers the right half of the left N photosensitive pixels and the lefthalf of the right N photosensitive pixels in the focusing photosensitiveunit 11, or covers the lower half of the upper N photosensitive pixelsand the upper half of the lower N photosensitive pixels in the focusingphotosensitive unit 11. The size and position covered by the whitefilter unit 21 in the focusing photosensitive unit 11 is not limited inthe present disclosure. As illustrated in FIG. 3, in an embodiment ofthe present disclosure, the white filter unit 21 (i.e. W in FIG. 3)covers the right half of the left 2 photosensitive pixels and the lefthalf of the right 2 photosensitive pixels in the focusing photosensitiveunit 11, and remaining part is formed of general filter units.

In general, in the dual-core focusing image sensor 100 according to theembodiments of the present disclosure, N*N photosensitive pixels formone group and share one first micro lens 31, and the white filter unit21 covers a part of the focusing photosensitive unit 11.

The array 30 of micro lenses may include a plurality of first microlenses 31.

For ease of understanding, the arrangement of first micro lenses 31 inthe array 30 of micro lenses will be described below with reference toaccompanying drawings. FIG. 4 is a schematic diagram illustrating adensity arrangement of first micro lenses. As illustrated in FIG. 4, thewhite filter units 21 covered by the first micro lenses 31 (i.e., W inFIG. 4) are scattered in the whole dual-core focusing image sensor, andoccupy 3% to 5% of the total number of pixels. The closer it is from thecenter of the array of micro lenses, the white filter units are arrangedmore densely, and the farther it is from the center of the array ofmicro lenses, the white filter units are arranged more sparsely, whichgives priority to focusing accuracy and speed in the middle area of thepicture, and effectively improves the focusing speed without affectingthe image quality.

In an embodiment of the present disclosure, the array 30 of micro lensesincludes a horizontal center line and a vertical center line. Theplurality of first micro lenses 31 include a first group of first microlenses 31 arranged along the horizontal center line and a second groupof first micro lenses 31 arranged along the vertical center line.

In an embodiment of the present disclosure, the array of micro lenses 30may further include two diagonals. In this case, the plurality of firstmicro lenses 31 also includes a third group of first micro lenses 31arranged along the two diagonals.

It should be noted that, W in FIG. 3 and FIG. 4 indicates that largeramount of passed light can be obtained when the white filter unit 21 isused.

Based on the structure of the dual-core focusing image sensor in FIG. 2to FIG. 4, the focusing control method for the dual-core focusing imagesensor according to embodiments of the present disclosure is describedbelow. FIG. 5 is a flow chart of a focusing control method for adual-core focusing image sensor according to an embodiment of thepresent disclosure. As illustrated in FIG. 5, the method may includefollowing.

At block 51, the array of photosensitive pixels is controlled to enter afocus mode.

When a camera is used to take pictures, and a sharpness of the pictureis insufficient, the array of photosensitive pixels can be controlled toenter the focus mode, thus improving the sharpness of the picture byfocusing.

At block 52, first phase difference information of the focusingphotosensitive unit and second phase difference information of thephotosensitive pixel corresponding to the second micro lens (thedual-core focusing photosensitive pixel) are obtained.

In an embodiment of the present disclosure, after entering the focusmode, the first phase difference information of the focusingphotosensitive unit and the second phase difference information of thephotosensitive pixel corresponding to the second micro lens may beobtained.

In at least one embodiment of the present disclosure, the first phasedifference information of the focusing photosensitive unit may beobtained as follows. Output values of a first part of photosensitivepixels in the focusing photosensitive unit are read as a first outputvalue, output values of a second part of photosensitive pixels in thefocusing photosensitive unit are read as a second output value, and thefirst phase difference information is obtained according to the firstoutput value and the second output value.

It should be noted that, in embodiments of the present disclosure,obtaining the first phase difference information of the focusingphotosensitive pixel may refer to obtaining the first phase differenceinformation of the part of the focusing photosensitive unit covered bythe white filter unit.

With reference to FIG. 3 and FIG. 6, illustration will be made below bytaking the focusing photosensitive unit including 2*2 photosensitivepixels, and the white filter unit covering the right half of the left 2photosensitive pixels and the left half of the right 2 photosensitivepixels in the focusing photosensitive unit as an example. The areacovered by the white filter unit (the white part in FIG. 3, denoted byW) in the focusing photosensitive unit can be divided from differentviewpoints. As illustrated in FIG. 6, W is divided along a verticaldirection, along a horizontal direction and along a diagonal,respectively.

In a first example, W is divided along the vertical direction.

In this embodiment, W is divided into two parts which are left and rightparts. The output values of two “1”s in the left part of W are obtainedas the first output value, and the output values of two “2”s in theright part of W are obtained as the second output value.

In a second example, W is divided along the horizontal direction.

In this embodiment, W is divided into two parts which are upper andlower parts. The output values of two “1”s in the upper part of W areobtained as the first output value, and the output values of two “2”s onthe lower part of W are obtained as the second output value.

In a third example, W is divided along the diagonal.

In this embodiment, W is divided into two parts along the two diagonals.The output values of two “1” s in the upper left and the lower rightparts of W are obtained as the first output value, and the output valuesof two “2”s in the lower left and the upper right parts are obtained asthe second output value.

In embodiments of the present disclosure, after the first output valueand the second output value are obtained, the first phase informationcan be obtained according to the first output value and the secondoutput value.

For example, the output values of the two “1” s in the left part of Ware added to generate the first phase information, and the output valuesof the two “2”s in the right part of W are added to generate the secondphase information. Finally, the first phase difference information maybe obtained by calculating the difference value between the first phaseinformation and the second phase information.

In embodiments of the present disclosure, by taking the output values ofthe left part and the right part of the area covered by the white filterunit in the focusing photosensitive unit as the first output value andthe second output value respectively, the first phase differenceinformation in a left/right direction can be detected. By taking theoutput values of the upper part and the lower part of the area coveredby the white filter unit in the focusing photosensitive unit as thefirst output value and the second output value respectively, the firstphase difference information in an up/down direction can be detected. Bytaking the output values of the two diagonal parts of the area coveredby the white filter unit in the focusing photosensitive unit as thefirst output value and the second output value respectively, the firstphase difference information in a diagonal direction can be detected.

In at least one embodiment of the present disclosure, the second phasedifference information of the dual-core focus photosensitive pixel maybe obtained as follows. An output value of the first photodiode isobtained as a third output value, an output value of the secondphotodiode is obtained as a fourth output value, and the second phasedifference information is obtained according to the third output valueand the fourth output value.

Still taking FIG. 3 as an example, for respective dual-core focusphotosensitive pixels, the second phase difference information iscalculated in the same manner. Here, the second phase differenceinformation at Gr in FIG. 3 is illustrated as an example. The outputvalue of “1” at Gr is read as the third output value first, and then theoutput value of “2” at Gr is read as the fourth output value. The secondphase difference information is obtained according to the third outputvalue and the fourth output value. For example, the second phasedifference information can be obtained by calculating the differencevalue between the third output value and the fourth output value.

At block 53, focusing control is performed according to the first phasedifference information and the second phase difference information.

In embodiments of the present disclosure, after the first phasedifference information of the focusing photosensitive unit and thesecond phase difference information of the dual-core focusphotosensitive pixel are obtained, the focusing control can be performedaccording to the first phase difference information and the second phasedifference information.

In the conventional dual-core focusing technology, the phase differencevalue is usually calculated according to the output values of twophotodiodes in the dual-core focus photosensitive pixel, therebycalculating the driving force and the driving direction of the lens toachieve focusing. In the low light environment, the focusing speed isslow.

In embodiments of the present disclosure, one first micro lens iscorresponding to one white filter unit, and one white filter unit iscorresponding to one focusing photosensitive unit. By adapting the whitefilter unit, a larger amount of passed light can be obtained in the lowlight environment, thus improving the focusing speed in the low lightenvironment.

In the present disclosure, by inserting some larger micro lenses in thearray of micro lenses and placing the white filter unit on a part of thefocusing photosensitive unit, and by reading the first phase differenceinformation of the focusing photosensitive unit and the second phasedifference information of the dual-core focus photosensitive pixel, andperforming focusing control according to the first phase differenceinformation and the second phase difference information, it is possibleto increase the amount of light passing through the focusing pixels, andeffectively improve the focusing speed in low light environment, whileensuring the accuracy of color reduction of the image.

It should be understood that, the purpose of focusing is to obtainpictures with higher definition. In an actual application, after thefocusing processing is completed, the imaging processing may beperformed. Therefore, as illustrated in FIG. 7, and on the basis of FIG.5, after block 53, the method further includes following.

At block 71, the array of photosensitive pixels is controlled to enteran imaging mode.

In embodiments of the present disclosure, after the focusing control iscompleted, the array of photosensitive pixels can be controlled to enterthe imaging mode.

At block 72, the array of photosensitive pixels is controlled to performexposure, pixel values of the array of photosensitive pixels areobtained, and an image is generated.

The pixel values of the part of the focusing photosensitive unit coveredby the white filter unit are obtained by an interpolation algorithm.

In embodiments of the present disclosure, after the array ofphotosensitive pixels enters the imaging mode, the array ofphotosensitive pixels is controlled to perform exposure, the pixelvalues of the array of photosensitive pixels are obtained by reading theoutput values of the array of photosensitive pixels, and then the imageis generated.

In an embodiment of the present disclosure, for the dual-core focusingphotosensitive pixel (i.e., the photosensitive pixel corresponding tothe second micro lens), the pixel value is obtained by reading theoutput values of two photodiodes in the dual-core focusingphotosensitive pixel and adding the output values and the twophotodiodes. For the part of the focusing photosensitive unit covered bythe white filter unit, the pixel value is obtained by an interpolationalgorithm. In an embodiment of the present disclosure, the interpolationalgorithm may be any one of a nearest neighbor interpolation algorithm,a bilinear interpolation algorithm, and a cubic convolutioninterpolation algorithm.

For simplicity, the pixel values of the focusing photosensitive unit canbe obtained by the nearest neighbor interpolation algorithm.

FIG. 8 is a schematic diagram of obtaining pixel values of a focusingphotosensitive unit by an interpolation algorithm.

As illustrated in FIG. 8, in the focusing photosensitive unit including2*2 photosensitive pixels, the white filter unit (the white area in FIG.8) covers the right half of the left 2 photosensitive pixels and theleft half of the right 2 photosensitive pixels in the focusingphotosensitive unit. In order to output images with better quality, itis necessary to obtain the output value of the covered part in eachphotosensitive pixel by interpolation, i.e., it is necessary to obtainRGB values of the covered part in each photosensitive pixel byinterpolation. An average value of neighboring pixels may be taken asthe pixel value of the covered part in the photosensitive pixel. In anexample, the RGB values at upper left “1” in the white filter unit arecalculated. For convenience of description, the R pixel value at upperleft “1” is denoted as R₁₀, the G pixel value is denoted as G₁₀, and theB pixel value is denoted as B₁₀. The formulas are as follows.

R₁₀ = R$G_{10} = {\frac{G_{r\; 11} + G_{b\; 07} + {2g} + {2G}}{4} \times \frac{1}{2}}$$B_{10} = {\frac{B_{06} + B_{07} + B_{11} + {2B}}{4} \times \frac{1}{2}}$

It should be noted that, the RGB values at lower left “1”, upper right“2” and lower right “2” in the white filter unit may be calculatedsimilar to those of the upper left “1”, which are obtained byinterpolation based on neighboring pixel points and will not beelaborated herein.

It should be noted that, the foregoing description of the algorithm forobtaining the pixel values of the focusing photosensitive unit is onlyused to explain the present disclosure, and should not be understood aslimitation to the present disclosure. In actual processing, in order toobtain more accurate pixel values, the neighboring pixels can beunderstood in a board sense. For example, as illustrated in FIG. 8, R₁₁,R₀₇ and the like may also be used to calculate the pixel value of theupper left “1”. In an embodiment of the present disclosure, a higherweight is assigned to the pixel values of pixels nearer to the whitefilter unit-covered part of the photosensitive pixel, and a less weightis assigned to the pixel values of pixels farther from the covered partof the photosensitive pixel. In other words, the weight of the pixelvalue is inversely proportional to the distance from the pixel to thewhite filter unit-covered part of the photosensitive pixel.

In embodiments of the present disclosure, after the pixel values of thephotosensitive pixels are obtained, the image can be generated accordingto the pixel values of respective photosensitive pixels.

In the focusing control method for the dual-core focusing image sensoraccording to embodiments of the present disclosure, after the focusingcontrol is completed, the array of photosensitive pixels is controlledto enter the imaging mode, the array of photosensitive pixels iscontrolled to perform exposure, and the pixel values of the array ofphotosensitive pixels are obtained by reading the output value of thephotosensitive pixels, and then the image is generated, which improvesthe image quality.

In order to implement the above embodiments, the present disclosurefurther provides an electronic device. FIG. 9 is a block diagram of anelectronic device according to an embodiment of the present disclosure.

As illustrated in FIG. 9, the electronic device 900 includes thedual-core focusing image sensor 100 of the above embodiments of thepresent disclosure and a controller 910.

The controller 910 is configured to control the array of photosensitivepixels to enter a focus mode, read first phase difference information ofthe focusing photosensitive unit and second phase difference informationof the photosensitive pixel corresponding to the second micro lens, andperform focusing control according to the first phase differenceinformation and the second phase difference information.

It should be noted that, in embodiments of the present disclosure,obtaining the first phase difference information of the focusingphotosensitive unit may refer to obtain the first phase differenceinformation of the part of the focusing photosensitive unit covered bythe white filter unit.

In an embodiment of the present disclosure, the photosensitive pixel inthe dual-core focusing image sensor 100 has two photodiodes, which arethe first photodiode and the second photodiode. Therefore, thecontroller 910 is further configured to obtain an output value of thefirst photodiode as a third output value, obtain an output value of thesecond photodiode as a fourth output value, and obtain the second phasedifference information according to the third output value and thefourth output value.

It should be understood that, the purpose of focusing is to obtainpicture with higher definition. In the actual application, after thefocusing processing is completed, the imaging processing may beperformed. Therefore, in an embodiment of the present disclosure, thecontroller 910 is further configured to control the array ofphotosensitive pixels to enter an imaging mode, control the array ofphotosensitive pixels to perform exposure, obtain pixel values of thearray of photosensitive pixels and generate an image.

The pixel values of the part of the focusing photosensitive unit coveredby the white filter unit are obtained by an interpolation algorithm.With respect to details of calculating the pixel values, reference maybe made to the above description in method embodiments, which will notbe elaborated here.

With the electronic device according to embodiments of the presentdisclosure, by inserting some larger micro lenses in the array of microlenses and placing the white filter unit on a part of the focusingphotosensitive unit, and by reading the first phase differenceinformation of the focusing photosensitive unit and the second phasedifference information of the dual-core focus photosensitive pixel, andperforming focusing control according to the first phase differenceinformation and the second phase difference information, it is possibleto increase the amount of light passing through the focusing pixels, andeffectively improve the focusing speed in low light environment, whileensuring the accuracy of color reduction of the image.

In order to implement the above embodiments, the present disclosurefurther provides an electronic device. FIG. 10 is a block diagram of anelectronic device according to an embodiment of the present disclosure.

As illustrated in FIG. 10, the electronic device 1000 includes a housing1001, a processor 1002, a memory 1003, a circuit board 1004, and a powersupply circuit 1005. The circuit board 1004 is arranged inside a spaceenclosed by the housing 1001. The processor 1002 and the memory 1003 arepositioned on the circuit board 1004. The power supply circuit 1005 isconfigured to provide power for respective circuits or components of theelectronic device 1000. The memory 1003 is configured to storeexecutable program codes. The processor 1002 is configured to run aprogram corresponding to the executable program codes by reading theexecutable program codes stored in the memory 1003, to perform thefocusing control method for the dual-core focusing image sensoraccording to the above embodiments of the present disclosure.

With the electronic device according to embodiments of the presentdisclosure, by inserting some larger micro lenses in the array of microlenses and placing the white filter unit on a part of the focusingphotosensitive unit, and by reading the first phase differenceinformation of the focusing photosensitive unit and the second phasedifference information of the dual-core focus photosensitive pixel, andperforming focusing control according to the first phase differenceinformation and the second phase difference information, it is possibleto increase the amount of light passing through the focusing pixels, andeffectively improve the focusing speed in low light environment, whileensuring the accuracy of color reduction of the image.

It should be noted that the relational terms herein, such as “first” and“second”, are used only for differentiating one entity or operation,from another entity or operation, which, however do not necessarilyrequire or imply that there should be any real relationship or sequence.Moreover, the terms “comprise”, “include” or any other variationsthereof are meant to cover non-exclusive including, so that the process,method, article or device comprising a series of elements do not onlycomprise those elements, but also comprise other elements that are notexplicitly listed or also comprise the inherent elements of the process,method, article or device. In the case that there are no morerestrictions, an element qualified by the statement “comprises a . . . ”does not exclude the presence of additional identical elements in theprocess, method, article or device that comprises the said element.

The logic and/or steps described in other manners herein or shown in theflow chart, for example, a particular sequence table of executableinstructions for realizing the logical function, may be specificallyachieved in any computer-readable medium to be used by the instructionexecution system, device or equipment (such as the system based oncomputers, the system comprising processors or other systems capable ofobtaining the instruction from the instruction execution system, deviceand equipment and executing the instruction), or to be used incombination with the instruction execution system, device and equipment.As to the specification, “the computer-readable medium” may be anydevice adaptive for including, storing, communicating, propagating ortransferring programs to be used by or in combination with theinstruction execution system, device or equipment. More specificexamples of the computer-readable medium comprise but are not limitedto: an electronic connection (an electronic device) with one or morewires, a portable computer enclosure (a magnetic device), a randomaccess memory (RAM), a read only memory (ROM), an erasable programmableread-only memory (EPROM or a flash memory), an optical fiber device, anda portable compact disk read-only memory (CDROM). In addition, thecomputer readable medium may even be a paper or other appropriate mediumcapable of printing programs thereon, this is because, for example, thepaper or other appropriate medium may be optically scanned and thenedited, decrypted or processed with other appropriate methods whennecessary to obtain the programs in an electric manner, and then theprograms may be stored in the computer memories.

It should be understood that each part of the present disclosure may berealized by the hardware, software, firmware or their combination. Inthe above embodiments, a plurality of steps or methods may be realizedby the software or firmware stored in the memory and executed by theappropriate instruction execution system. For example, if it is realizedby the hardware, likewise in another embodiment, the steps or methodsmay be realized by one or a combination of the following techniquesknown in the art: a discrete logic circuit having a logic gate circuitfor realizing a logic function of a data signal, an application-specificintegrated circuit having an appropriate combination logic gate circuit,a programmable gate array (PGA), a field programmable gate array (FPGA),etc.

It should be noted that, reference throughout this specification to “anembodiment,” “some embodiments,” “an example,” “a specific example,” or“some examples,” means that a particular feature, structure, material,or characteristic described in connection with the embodiment or exampleis included in at least one embodiment or example of the presentdisclosure. Thus, the schematic expressions of the above-mentionedphrases throughout this specification are not necessarily referring tothe same embodiment or example of the present disclosure. Furthermore,the particular features, structures, materials, or characteristics canbe combined in any suitable manner in any one or more embodiments orexamples. In addition, in the case that it is not contradictory, aperson of skilled in the art can combine different embodiments orexamples and the features of different embodiments or examples.

It should be noted that, reference throughout this specification to “anembodiment,” “some embodiments,” “an example,” “a specific example,” or“some examples,” means that a particular feature, structure, material,or characteristic described in connection with the embodiment or exampleis included in at least one embodiment or example of the presentdisclosure. Thus, the schematic expressions of the above-mentionedphrases throughout this specification are not necessarily referring tothe same embodiment or example of the present disclosure. Furthermore,the particular features, structures, materials, or characteristics canbe combined in any suitable manner in any one or more embodiments orexamples. In addition, different embodiments or examples and features ofdifferent embodiments or examples described in the specification may becombined by those skilled in the art without mutual contradiction.

Reference throughout this specification to “an embodiment,” “someembodiments,” “an example,” “a specific example,” or “some examples,”means that a particular feature, structure, material, or characteristicdescribed in connection with the embodiment or example is included in atleast one embodiment or example of the present disclosure. Thus, theschematic expressions of the above-mentioned phrases throughout thisspecification are not necessarily referring to the same embodiment orexample of the present disclosure. Furthermore, the particular features,structures, materials, or characteristics can be combined in anysuitable manner in any one or more embodiments or examples. In addition,different embodiments or examples and features of different embodimentsor examples described in the specification may be combined by thoseskilled in the art without mutual contradiction.

Although embodiments of present disclosure have been shown and describedabove, it should be understood that above embodiments are justexplanatory, and cannot be construed to limit the present disclosure,for those skilled in the art, changes, alternatives, and modificationscan be made to the embodiments without departing from spirit, principlesand scope of the present disclosure.

What is claimed is:
 1. A focusing control method for a dual-corefocusing image sensor, wherein the dual-core focusing image sensorcomprises an array of photosensitive pixels, an array of filter unitsarranged on the array of photosensitive pixels, and an array of microlenses arrange above the array of filter units, the array ofphotosensitive pixels comprises at least one first micro lens and aplurality of second micro lenses, each second micro lens iscorresponding to one photosensitive pixel, each first micro lens iscorresponding to one focusing photosensitive unit, each focusingphotosensitive unit comprises N*N photosensitive pixels, and at least apart of the focusing photosensitive unit is covered by a white filterunit, where N is an even number greater than or equal to 2, the methodcomprises: controlling the array of photosensitive pixels to enter afocus mode; obtaining first phase difference information of the focusingphotosensitive unit and second phase difference information of thephotosensitive pixel corresponding to the second micro lens; andperforming focusing control according to the first phase differenceinformation and the second phase difference information.
 2. The methodaccording to claim 1, wherein obtaining first phase differenceinformation of the focusing photosensitive unit comprises: obtaining afirst output value according to output values of a first part ofphotosensitive pixels in the focusing photosensitive unit; obtaining asecond output value according to output values of a second part ofphotosensitive pixels in the focusing photosensitive unit; andgenerating the first phase difference information according to the firstoutput value and the second output value.
 3. The method according toclaim 1, wherein each photosensitive pixel has a first photodiode and asecond photodiode, and obtaining second phase difference information ofthe photosensitive pixel comprises: obtaining a third output valueaccording to an output value of the first photodiode of thephotosensitive pixel; obtaining a fourth output value according to anoutput value of the second photodiode of the photosensitive pixel; andgenerating the second phase difference information according to thethird output value and the fourth output value.
 4. The method accordingto claim 1, further comprising: controlling the array of photosensitivepixels to enter an imaging mode; and controlling the array ofphotosensitive pixels to perform exposure, obtaining pixel values of thearray of photosensitive pixels and generating an image, wherein thepixel values of the part of the focusing photosensitive unit covered bythe white filter unit are obtained by an interpolation algorithm.
 5. Adual-core focusing image sensor, comprising: an array of photosensitivepixels; an array of filter units arranged on the array of photosensitivepixels; and an array of micro lenses arranged above the array of filterunits, comprising at least one first micro lens and a plurality ofsecond micro lenses, each second micro lens corresponding to onephotosensitive pixel, each first micro lens corresponding to onefocusing photosensitive unit, each focusing photosensitive unitcomprising N*N photosensitive pixels, and at least a part of thefocusing photosensitive unit being covered by a white filter unit, whereN is an even number greater than or equal to 2; wherein, the array ofmicro lenses comprises a plurality of first micro lenses, and density ofthe plurality of first micro lenses is higher towards a center of thearray of micro lenses as compared to a periphery of the array of microlenses.
 6. The dual-core focusing image sensor according to claim 5,wherein, the photosensitive pixels are arranged in a Bayer array.
 7. Thedual-core focusing image sensor according to claim 5, wherein, the arrayof micro lenses comprises a plurality of first micro lenses.
 8. Thedual-core focusing image sensor according to claim 5, wherein the arrayof micro lenses comprises a horizontal center line and a vertical centerline, and the plurality of first micro lenses comprise: a first group offirst micro lenses arranged along the horizontal center line; and asecond group of first micro lenses arranged along the vertical centerline.
 9. The dual-core focusing image sensor according to claim 8,wherein the array of micro lenses comprises two diagonals, and theplurality of first micro lenses further comprise: a third group of firstmicro lenses arranged along the two diagonals.
 10. The dual-corefocusing image sensor according to claim 5, wherein, the white filterunit is configured to cover a right half of left N photosensitive pixelsand a left half of right N photosensitive pixels in the focusingphotosensitive unit.
 11. The dual-core focusing image sensor accordingto claim 10, wherein N=2.
 12. An electronic device, comprising: adual-core focusing image sensor, comprising: an array of photosensitivepixels; an array of filter units arranged on the array of photosensitivepixels; and an array of micro lenses arranged above the array of filterunits, comprising at least one first micro lens and a plurality ofsecond micro lenses, each second micro lens corresponding to onephotosensitive pixel, each first micro lens corresponding to onefocusing photosensitive unit, each focusing photosensitive unitcomprising N*N photosensitive pixels, and at least a part of thefocusing photosensitive unit being covered by a white filter unit, whereN is an even number greater than or equal to 2; and a controller,configured to: control the array of photosensitive pixels to enter afocus mode; obtain first phase difference information of the focusingphotosensitive unit and second phase difference information of thephotosensitive pixel corresponding to the second micro lens; and performfocusing control according to the first phase difference information andthe second phase difference information.
 13. The electronic deviceaccording to claim 12, wherein, the controller is configured to: obtaina first output value according to output values of a first part ofphotosensitive pixels in the focusing photosensitive unit; obtain asecond output value according to output values of a second part ofphotosensitive pixels in the focusing photosensitive unit; and generatethe first phase difference information according to the first outputvalue and the second output value.
 14. The electronic device accordingto claim 12, wherein, each photosensitive pixel has a first photodiodeand a second photodiode, and the controller is configured to: obtain athird output value according to an output value of the first photodiodeof the photosensitive pixel; obtain a fourth output value according toan output value of the second photodiode of the photosensitive pixel;and generate the second phase difference information according to thethird output value and the fourth output value.
 15. The electronicdevice according to claim 12, wherein, the controller is configured to:control the array of photosensitive pixels to enter an imaging mode; andcontrol the array of photosensitive pixels to perform exposure, obtainpixel values of the array of photosensitive pixels and generate animage, wherein, the pixel values of the part of the focusingphotosensitive unit covered by the white filter unit are obtained by aninterpolation algorithm.
 16. The electronic device according to claim12, wherein, the array of micro lenses comprises a plurality of firstmicro lenses, wherein the closer it is from a center of the array ofmicro lenses, the higher a density of the first micro lenses is, and thefarther it is from the center of the array of micro lenses, the less thedensity of the first micro lenses is.
 17. The electronic deviceaccording to claim 16, wherein the array of micro lenses comprises ahorizontal center line and a vertical center line, and the plurality offirst micro lenses comprise: a first group of first micro lensesarranged along the horizontal center line; and a second group of firstmicro lenses arranged along the vertical center line.
 18. The electronicdevice according to claim 1, wherein the array of micro lenses comprisestwo diagonals, and the plurality of first micro lenses further comprise:a third group of first micro lenses arranged along the two diagonals.19. The electronic device according to claim 12, wherein, the whitefilter unit is configured to cover a right half of left N photosensitivepixels and a left half of right N photosensitive pixels in the focusingphotosensitive unit, where N=2.